﻿using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace CMS6Tools.Management.Controls
{
    public delegate void CheckBoxClickedHandler(int columnIndex, bool state);
    public class DatagridViewCheckBoxHeaderCell : DataGridViewColumnHeaderCell
    {
        private Point checkBoxLocation;
        private Size checkBoxSize;
        private bool _checked = false;
        private Point _cellLocation = new Point();
        private System.Windows.Forms.VisualStyles.CheckBoxState _cbState = System.Windows.Forms.VisualStyles.CheckBoxState.UncheckedNormal;
        public event CheckBoxClickedHandler OnCheckBoxClicked;
        public string HeaderText { get; set; }

        public DatagridViewCheckBoxHeaderCell()
        {
            HeaderText = string.Empty;
        }

        protected override void Paint(System.Drawing.Graphics graphics,
            System.Drawing.Rectangle clipBounds,
            System.Drawing.Rectangle cellBounds,
            int rowIndex,
            DataGridViewElementStates dataGridViewElementState,
            object value,
            object formattedValue,
            string errorText,
            DataGridViewCellStyle cellStyle,
            DataGridViewAdvancedBorderStyle advancedBorderStyle,
            DataGridViewPaintParts paintParts)
        {
            base.Paint(graphics, clipBounds, cellBounds, rowIndex,
                dataGridViewElementState,
               HeaderText == null ? value : HeaderText,
                HeaderText == null ? formattedValue : HeaderText,
                errorText,
                cellStyle,
                advancedBorderStyle,
                paintParts);
            Point p = new Point();
            Size s = CheckBoxRenderer.GetGlyphSize(graphics,
            System.Windows.Forms.VisualStyles.CheckBoxState.UncheckedNormal);
            p.X = cellBounds.Location.X +
            (cellBounds.Width / 2) - (s.Width / 2);
            p.Y = cellBounds.Location.Y +
            (cellBounds.Height / 2) - (s.Height / 2);
            _cellLocation = cellBounds.Location;
            checkBoxLocation = p;
            checkBoxSize = s;
            if (_checked)
                _cbState = System.Windows.Forms.VisualStyles.
                CheckBoxState.CheckedNormal;
            else
                _cbState = System.Windows.Forms.VisualStyles.
                CheckBoxState.UncheckedNormal;
            CheckBoxRenderer.DrawCheckBox
            (graphics, checkBoxLocation, _cbState);
        }

        protected override void OnMouseClick(DataGridViewCellMouseEventArgs e)
        {
            Point p = new Point(e.X + _cellLocation.X, e.Y + _cellLocation.Y);
            if (p.X >= checkBoxLocation.X && p.X <=
            checkBoxLocation.X + checkBoxSize.Width
            && p.Y >= checkBoxLocation.Y && p.Y <=
            checkBoxLocation.Y + checkBoxSize.Height)
            {
                _checked = !_checked;
                if (OnCheckBoxClicked != null)
                {
                    OnCheckBoxClicked(e.ColumnIndex, _checked);
                    this.DataGridView.InvalidateCell(this);
                }
            }
            base.OnMouseClick(e);
        }

    }
    public class DataGridViewColumnSelector
    {
        // the DataGridView to which the DataGridViewColumnSelector is attached
        private DataGridView mDataGridView = null;
        // a CheckedListBox containing the column header text and checkboxes
        private CheckedListBox mCheckedListBox;
        // a ToolStripDropDown object used to show the popup
        private ToolStripDropDown mPopup;

        /// <summary>
        /// The max height of the popup
        /// </summary>
        public int MaxHeight = 300;
        /// <summary>
        /// The width of the popup
        /// </summary>
        public int Width = 200;

        /// <summary>
        /// Gets or sets the DataGridView to which the DataGridViewColumnSelector is attached
        /// </summary>
        public DataGridView DataGridView
        {
            get { return mDataGridView; }
            set
            {
                // If any, remove handler from current DataGridView 
                if (mDataGridView != null) mDataGridView.CellMouseClick -= new DataGridViewCellMouseEventHandler(mDataGridView_CellMouseClick);
                // Set the new DataGridView
                mDataGridView = value;
                // Attach CellMouseClick handler to DataGridView
                if (mDataGridView != null) mDataGridView.CellMouseClick += new DataGridViewCellMouseEventHandler(mDataGridView_CellMouseClick);
            }
        }

        // When user right-clicks the cell origin, it clears and fill the CheckedListBox with
        // columns header text. Then it shows the popup. 
        // In this way the CheckedListBox items are always refreshed to reflect changes occurred in 
        // DataGridView columns (column additions or name changes and so on).
        void mDataGridView_CellMouseClick(object sender, DataGridViewCellMouseEventArgs e)
        {
            if (e.Button == MouseButtons.Right && e.RowIndex == -1 && e.ColumnIndex == 0)
            {
                mCheckedListBox.Items.Clear();
                foreach (DataGridViewColumn c in mDataGridView.Columns)
                {
                    mCheckedListBox.Items.Add(c.HeaderText, c.Visible);
                }
                int PreferredHeight = (mCheckedListBox.Items.Count * 16) + 7;
                mCheckedListBox.Height = (PreferredHeight < MaxHeight) ? PreferredHeight : MaxHeight;
                mCheckedListBox.Width = this.Width;
                mPopup.Show(mDataGridView.PointToScreen(new Point(e.X, e.Y)));
            }
        }

        // The constructor creates an instance of CheckedListBox and ToolStripDropDown.
        // the CheckedListBox is hosted by ToolStripControlHost, which in turn is
        // added to ToolStripDropDown.
        public DataGridViewColumnSelector()
        {
            mCheckedListBox = new CheckedListBox();
            mCheckedListBox.CheckOnClick = true;
            mCheckedListBox.ItemCheck += new ItemCheckEventHandler(mCheckedListBox_ItemCheck);

            ToolStripControlHost mControlHost = new ToolStripControlHost(mCheckedListBox);
            mControlHost.Padding = Padding.Empty;
            mControlHost.Margin = Padding.Empty;
            mControlHost.AutoSize = false;

            mPopup = new ToolStripDropDown();
            mPopup.Padding = Padding.Empty;
            mPopup.Items.Add(mControlHost);
        }

        public DataGridViewColumnSelector(DataGridView dgv)
            : this()
        {
            this.DataGridView = dgv;
        }

        // When user checks / unchecks a checkbox, the related column visibility is 
        // switched.
        void mCheckedListBox_ItemCheck(object sender, ItemCheckEventArgs e)
        {
            mDataGridView.Columns[e.Index].Visible = (e.NewValue == CheckState.Checked);
        }
    }
}
